Vane pump

ABSTRACT

A vane pump is configured to discharge a working fluid introduced into one side of a rotary chamber formed between an outer cam ring and a rotor to the other side of the rotary chamber, wherein a through slit extending in a circumferential direction of the outer cam ring is formed in a corresponding portion of the outer cam ring corresponding to the side to which the working fluid is introduced into the rotary chamber.

TECHNICAL FIELD

The present invention relates to a vane pump which is capable of smoothly suctioning a working fluid suctioned into a rotary chamber while minimizing damage to a vane or occurrence of noise, exhibits an excellent performance in terms of flow rate and volumetric efficiency, and is capable of effectively reducing inner cavitation.

BACKGROUND ART

Pumps function to supply a working fluid to each portion of an engine to smoothly operating the engine, are configured to apply a pressure to the working fluid using mechanical energy of the engine such as a motor, an internal combustion engine, or a steam engine and then circulate the working fluid to each portion of the engine, and are classified into vane-type pumps and piston-type pumps.

Meanwhile, pumps include constant-volume pumps having constant discharge quantities under load variation and variable-capacity pumps having varying discharge quantities according to load variation.

As illustrated in FIGS. 1 to 2 A, a variable-capacity vane pump, which is a vane-type pump and has a discharge quantity varying according to load variation, includes: a casing 10 including a housing 11 and a cover 12; a rotor 30 rotating according to rotation of a driving shaft; an outer cam ring 20 installed eccentric to the rotor 30; a support spring 60 which elastically supports the outer cam ring 20, and maintains the state in which the outer cam ring 20 and the rotor 30 are positioned eccentric to each other; and a plurality of vanes 31 which rotate while contacting the inner circumferential surface of the outer cam ring 20 and thereby delivers a pressurized working fluid to the outside.

FIG. 3 is a perspective view illustrating an inside of an outer cam ring 20, and FIG. 4 is a view for illustrating a process in which a working fluid is introduced into a rotary chamber in a conventional variable-capacity vane-type pump. The conventional outer cam ring 20 is formed such that a working fluid is suctioned into the rotary chamber RS through a suctioning port 40 communicating with an upper opening and a lower opening, which correspond to one side of the rotary chamber RS, is transported under pressure applied by vanes 31 to the other side of the rotary chamber RS, and is then discharged through a discharge port 50 communicating with the upper opening and the lower opening which correspond to the other side of the rotary chamber RS.

However, the conventional outer cam ring 20 had a limitation in that the working fluid suctioned into the rotary chamber RS could not be smoothly suctioned due to suction resistance of the working fluid suctioned, and thus, cavitation or noise occurred.

To solve this, as illustrated in FIG. 5, a vane pump, which was for continuously variable transmissions and had a multilayer suctioning flow passage, was disclosed in Korea Patent Publication No. 10-2014-010467. However, also in the case of the vane pump, which was for continuously variable transmissions and was disclosed in the Koran Laid-open Patent Publication, a circular through hole b is simply formed in the cam ring 80 to solve the above-mentioned limitation, but the effect thereof was unsatisfactory.

In addition, stepped parts a were formed in the upper and lower portions of the cam ring 80 so as to smoothly suction the working fluid, but shaking of the vanes was caused due to the stepped parts a, and therefore, a smooth pressure-transport could not be carried out, and further, the stepped parts a caused damage to the vanes and noise.

Thus, the structures of vane pumps have been demanded to be improved not only to effectively prevent cavitation or noise but also to smoothly suction the working fluid.

RELATED ART DOCUMENT

Korean Patent Publication No. 10-2014-0104671 (Published on Aug. 29, 2014)

DISCLOSURE OF THE INVENTION Technical Problem

An objective of the present invention for solving the limitations of conventional arts is to provide a vane pump which is capable of smoothly suctioning a working fluid suctioned into a rotary chamber while suppressing damage to a vanes or occurrence of noise, has an excellent performance in terms of flow rate and volumetric efficiency, and is capable of effectively reducing inner cavitation.

Technical Solution

To this end, the vane pump of the present invention is configured such that the working fluid introduced into one side of the rotary chamber formed between an outer cam ring and a rotor is discharged to the other side of the rotary chamber, wherein a through slit extending along the circumferential direction of the outer cam ring is formed in the corresponding portion of the outer cam ring corresponding to the side to which the working fluid is introduced.

In an embodiment, an upper end portion of the outer cam ring having a through slit formed therein may be formed in the same height as the remaining upper end portion of the outer ring, and a lower end portion of the outer cam ring having the through slit formed therein may be formed in the same height as the remaining lower end portion of the outer ring.

In an embodiment, in the cam ring, an inside of the upper end portion and an inside of the lower end portion the outer cam ring which have through slits formed therein may be chamfered.

In an embodiment, the upper end portion of the outer cam ring having the through slit formed therein and the lower end portion of the outer cam ring having the through slit formed therein may be formed in a same height, the through slit may be formed in height at least two times the thickness of the upper end portion or the lower end portion of the outer cam ring having the through slit, and thus, the through slit may be formed in rectangular shapes.

In an embodiment, the through slit may be formed in a width 2.5 to 3 times the thickness of the upper end portion or lower end portion of the outer cam ring having the through slit formed therein.

In an embodiment, the upper and lower end portions of the outer cam ring having the through slit formed therein are formed in a thickness which gradually increases in an opposite direction to a moving direction of the working fluid, and the through slit may correspondingly be formed in a width which gradually increases.

In an embodiment, the upper and lower end portions of the outer cam ring having the through slit formed therein may be formed vertically symmetrical to each other.

In an embodiment, the through slit may extend up to an end portion corresponding to the opposite side of a moving direction of the working fluid in a suction port configured to communicate with the rotary chamber on the side to which the working fluid is introduced.

Advantageous Effects

The present invention described above relates to a vane pump has a merit of being capable of smoothly drawing a working fluid drawn into a rotary chamber while minimizing damage to a vane or occurrence of noise, having an excellent performance in terms of flow rate and volumetric efficiency, and being capable of effectively reducing inner cavitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating a conventional vane pump.

FIG. 2 is a partial exploded perspective view illustrating a conventional vane pump.

FIG. 3 is a perspective view illustrating an inside of an outer cam ring constituting a conventional vane pump.

FIG. 4 is a view for describing a process in which a working fluid is intruded into a rotary chamber in a conventional vane pump.

FIG. 5 is a perspective view illustrating a cam ring constituting a vane pump for a conventional continuously variable transmission having a multilayered suction flow passage.

FIG. 6 is a perspective view illustrating an outer cam ring constituting a vane pump according to a first embodiment of the present invention.

FIG. 7 is a perspective view illustrating an outer cam ring constituting a vane pump according to a second embodiment of the present invention.

FIG. 8 is an analysis result when a rotation speed of a pump is 6500 rpm in a cam ring provided in the vane pump for a conventional continuously variable transmission having a multilayered suction flow passage and in outer cam rings constituting vane pumps of the first and second embodiments.

FIG. 9 is an analysis result when a rotation speed of a pump is 12000 rpm in a cam ring provided in the vane pump for a conventional continuously variable transmission having a multilayered suction flow passage and in the outer cam rings constituting the vane pumps of the first and second embodiments.

FIG. 10 is a table in which flow rates, volume efficiencies, and remaining gas amounts when a rotation speeds of pumps are 6500 rpm and 12000 rpm in a cam ring provided in the vane pump for a conventional continuously variable transmission having a multilayered suction flow passage and in the outer cam rings constituting the vane pumps of the first and second embodiments.

MODE FOR CARRYING OUT THE INVENTION

The present invention may be implemented in various forms without departing form technical concepts and main features thereof. Thus, embodiments of the present invention are, in all aspects, merely simple exemplary examples, and should not be limitatively interpreted.

The terms such as “first” and “second” may be used to describe various components, but the components should not be limited by the terms.

The terms are used only for the purpose of discriminating one component from other components. For example, a first component may be named as a second component within the scope of the present disclosure, and likewise, the second component may be named as the first component.

The term “and/or” includes a combination of a plurality of related elements described or one among a plurality of the related elements described.

When a component is referred to as being “coupled” or “connected” to another component, the component may be directly coupled or connected to the another component, but another component may be present therebetween.

Conversely, when a component is referred to as being “directly coupled” or “connected” to another component, it should be understood that other component is not present therebetween.

The terms used in the present disclosure are used to describe only a specific embodiment, and are not used to limit the present disclosure. Singular representation includes plural representation unless otherwise noted clearly different in context.

In the present application, it should be understood that the terms such as “include”, “comprise”, and “have” are used to designate the presence of a feature, a number, a step, an operation, a component, or combinations thereof, but not to in advance exclude the possibility of the presence or addition of one or more of other features, numbers, steps, operations, components or combinations thereof.

Unless otherwise defined, all terms including technical or scientific terms used herein have the same meanings generally understood by a person skilled in the art belonging to the present invention.

Terms such as those defined in generally used dictionaries should be understood to have meaning coinciding with a meaning related technique has in context, and should not be understood as an ideal, excessively formal meaning unless otherwise clearly defined in the present application.

Hereinafter, with reference to accompanying drawings, preferred exemplary embodiments according to the present invention will be described in detail, like reference numeral is applied to like components which are the same as or corresponding to each other, and the overlapping descriptions thereon will not be provided.

In describing the present invention, when a detailed description about a related well-known art may obscure the gist of the present invention, the detailed description thereof will not be provided.

A vane pump according to an embodiment of the present invention is a vane pump configured such that a working fluid introduced into one side of a rotary chamber formed between an outer cam ring and a rotor is discharged to the other side of the rotary chamber, the entire components thereof may have a configuration similar to conventional vane pumps, and may be configured to include: a casing including a housing and a cover; a rotor rotating due to a rotation of a driving shaft; an outer cam ring eccentrically installed to the rotor; a support spring which elastically supports the outer cam ring and in which the outer cam ring and the rotor maintain a state of being located eccentric to each other; and a plurality of vanes which transports the working fluid under pressure to the outside while contacting an inner circumferential surface of the outer cam ring.

FIG. 6 is a perspective view illustrating an outer cam ring constituting a vane pump according to a first embodiment of the present invention, FIG. 7 is a perspective view illustrating an outer cam ring constituting a vane pump according to a second embodiment of the present invention, and hereinafter a shape of an outer cam ring constituting a configuration of a vane pump of the present invention will be described in detail.

As illustrated in FIGS. 6 and 7, outer cam rings 100 and 200 configuring a vane pump of the present invention have, on portions of the outer cam rings 100 and 200 corresponding to the side to which working fluids are introduced into rotary chambers, through slits 100 h and 200 h extending in the circumferential directions of the outer cam rings 100 and 200.

First, referring to FIG. 6, an outer cam ring 100 of the first embodiment will be described.

The outer cam ring 100 of the first embodiment has, on a portion thereof corresponding to the side to which the working fluid is introduced, a rectangular through slit 100 h which extends in the circumferential direction thereof.

Specifically, the upper end part 111 of the outer cam ring 100 has one portion in which the rectangular through slit 100 h is formed, and which is formed in the same height as the remaining portion thereof, and the lower end part 113 of the outer cam ring 100 has one portion, in which the rectangular through slit 100 h is formed, and which is formed in the same height as the remaining portion thereof. That is, the outer cam ring 100 is formed such that the upper and lower portions thereof are formed to be flat overall.

Meanwhile, the upper end part 111 of the outer cam ring 100 having the through slit 100 h formed therein and the lower end part 113 of the outer cam ring 100 having the through slit 100 h formed therein may favorably be formed in the same thickness, and in this case, and the through slit 100 h may favorably be formed in a height at least two times the thickness of the upper end part 111 or the lower end part 113 of the outer cam ring 100 at the portion having the through slit 100 h. Specifically, the through slit 100 h may favorably be formed in a height 2.5 to 3 times the thickness of the upper end portion 111 of the outer cam ring 100 having the through slit 100 h formed therein or the lower end portion 113 of the outer cam ring 100 having the through slit 100 h formed therein, and when the height formed falls out of this range, there may be a limitation of occurrence of cavitation or noise, or disadvantage of a decreased flow rate.

Meanwhile, insides of the upper end portion 111 and the lower end portion 113 of the outer cam ring 100, which have the through slit 100 h formed therein, may favorably be processed to have chamfers C, and thus, the working fluid may be smoothly introduced due to such chamfers C.

The through slit 100 h may extend up to an end portion corresponding to the opposite side of a moving direction A of the working fluid in the suction port which is configured to communicate with the rotary chamber on the side to which the working fluid is introduced.

Next, referring to FIG. 7, an outer cam ring 200 of the second embodiment will be described.

The outer cam ring 200 of the second embodiment has, on the corresponding portion of the outer cam ring 200 corresponding to the side where the working fluid is introduced into a rotary chamber, a through slit 200 h which has a shape of an approximate isosceles triangle and extends in the circumferential direction of the outer cam ring 200. That is, an upper end part 211 and a lower end part 213 of the outer cam ring 100 respectively have portions which have the through slit 200 h formed therein and are formed to be vertically symmetrical to each other.

Specifically, the upper end part 211 and the lower end part 213 of the outer cam ring 200 have portions which have the through slit with an isosceles triangle shape 200 h formed therein, the portions being formed to have heights which gradually increase in the opposite direction to a moving direction A of he working fluid, and corresponding to this, the through slit 200 h is formed to have a width which gradually increases, and similarly to the first embodiment, the upper portion and the lower portion of the outer cam ring 200 are formed to be flat overall.

Meanwhile, the portions corresponding to both sides of the through slit 200 h having an isosceles triangle shape are favorably formed not in a linear shape but in a smooth outwardly convex curve.

In addition, similarly to the first embodiment, insides of the upper end part 211 and the lower end part 213 of the outer cam ring 200 which have the through slit 200 h formed therein are favorably be processed to have chamfers C, and the working fluid may be smoothly introduced due to such chamfers C.

The through slit 200 h may extend up to an end portion corresponding to the opposite side of a moving direction A of the working fluid in the suction port which is configured to communicate with the rotary chamber on the side to which the working fluid is introduced.

FIG. 8 is an analysis result when the rotation speed of a pump is 6500 rpm, in a cam ring provided in a vane pump for a conventional continuously variable transmission having a multilayer suction flow passage, and in outer cam rings constituting vane pumps of the first and second embodiments.

As illustrated in FIG. 8, in the conventional case of simply perforating a circular hole in a cam ring, it may be confirmed that cavitation (gas) is still generated around the through hole, and it may be confirmed that cavitation (gas) generated around the through slits 100 h and 200 h is remarkably reduced in the outer cam rings 100 and 200 of the first and second embodiments of the present invention.

FIG. 9 is an analysis result when a rotation speed of a pump is 12000 rpm, in a cam ring provided in the vane pump for a conventional continuously variable transmission having a multilayer suction flow passage, and in the outer cam rings constituting the vane pumps of the first and second embodiments.

As illustrated in FIG. 9, it may be confirmed that when the rpm of a vane pump is a high speed, the generation of cavitation gas further increases, that in the conventional case, a great amount of cavitation (gas) is generated around the through slit, and that a small amount of cavitation (gas) is generated around the through slits 100 h and 200 h in the outer cam rings 100 and 200 of the first and second embodiments of the present invention.

FIG. 10 is a table in which flow rates, volumetric efficiencies, and remaining gas amounts when the rotation speeds of pumps are 6500 rpm and 12000 rpm, in a cam ring provided in the vane pump for a conventional continuously variable transmission having a multilayer suction flow passage, and in the outer cam rings constituting the vane pumps of the first and second embodiments.

As illustrated in FIG. 10, it may be confirmed that a vane pump, to which the outer cam rings 100 and 200 of the first and second embodiments are applied, has a higher flow rate and a higher volumetric efficiency than the conventional art, and a reduced amount of cavitation (gas) is generated.

As described above, the vane pump, to which the outer cam rings 100 and 200 of the first and second embodiments are applied, has a structure which may decrease demerits while further increasing merits such that the amount of generated cavitation gas decreases while a flow rate and a volumetric efficiency increase.

Preferred exemplary embodiments of the present invention has been described with reference to drawings, but it is obvious that a person skilled in the art could make many various, obvious modifications from the description without departing from the scope of the present invention. Thus, the scope of the present invention should be interpreted according to claims set forth herein to include such various modified examples. 

1. A vane pump configured to discharge a working fluid introduced into one side of a rotary chamber formed between an outer cam ring and a rotor to the other side of the rotary chamber, wherein a through slit extending in a circumferential direction of the outer cam ring is formed in a corresponding portion of the outer cam ring corresponding to the side to which the working fluid is introduced into the rotary chamber.
 2. The vane pump of claim 1, wherein an upper end portion of the outer cam ring having the through slit formed therein is formed in a same height as a remaining upper end portion of the outer cam ring, and a lower end portion of the outer cam ring having the through slit formed therein is formed in the same height as the remaining lower end portion of the outer ring.
 3. The vane pump of claim 1, insides of the upper end portion and the lower end portion of the outer cam ring having the through slit formed therein are chamfered.
 4. The vane pump of claim 1, the upper end portion of the outer cam ring having the through slit formed therein and the lower end portion of the outer cam ring having the through slit formed therein are formed in a same height, the through slit is formed in a width at least two times of the thickness of the upper end portion or the lower end portion of the outer cam ring having the through slit formed therein, and the through slit is thereby formed in rectangular shapes.
 5. The vane pump of claim 4, the through slit is formed in a width 2.5 to 3 times of the thickness of the upper end portion or lower end portion of the outer cam ring having the through slit formed therein.
 6. The vane pump of claim 1, the upper and lower end portions of the outer cam ring having the through slit formed therein are formed in thicknesses which gradually increase in an opposite direction to a moving direction of the working fluid, and the through slit is correspondingly formed in a width which gradually increases.
 7. The vane pump of claim 6, the upper and lower end portions of the outer cam ring having the through slit formed therein are formed vertically symmetrical to each other.
 8. The vane pump of claim 1, the through slit extends up to an end portion corresponding to the opposite side of a moving direction of the working fluid in a suction port configured to communicate with the rotary chamber on the side to which the working fluid is introduced. 